The restoration of a patient's tooth or teeth often includes the replacement of natural tooth structure by a manufactured dental restoration or dental prosthesis. Typically, a tooth that is to be restored is first prepared by a dentist to remove undesired tooth substance and to provide the tooth with a shape appropriate to receive the dental restoration. The dental restoration is typically mated precisely with the remaining tooth shape prepared by the dentist on the basis of an impression of the prepared tooth. Therefore the dental impression should be very precise, and should represent all tooth structure required to determine the shape of the mating surface of the later dental restoration. In particular, the dental impression should represent the transition or the “margin” between the shape prepared in a tooth and the natural tooth shape. For dental restorations that extend below a patient's gingiva (or gums), the dentist also should make the part of the margin accessible for the dental impression that would normally be covered by the gingiva. The procedure of displacing the gingiva from the tooth to make the margin accessible is also known as “gingival retraction” in the field of dentistry.
A common gingival retraction procedure includes the insertion of a retraction cord in the gingival sulcus, which displaces the gingiva from the tooth. However, the insertion of a retraction cord is relatively time consuming and is generally perceived as being relatively inconvenient for the dentist and uncomfortable for the patient. An alternative for the retraction cord is a gingival retraction paste, which is typically a high viscosity paste that is squeezed or injected into the gingival sulcus, thereby displacing the soft gingival tissue from the tooth. The gingival retraction paste in one example is provided in a syringe or applicator that is connectable with a metal dispensing cannula or needle. The cannula or needle dispenses the paste around a tooth towards the entry of the gingival sulcus to thereby squeeze it into the gingival sulcus.
However, soft tissue in the mouth is very sensitive and trauma to the tissue can occur when a metal device makes contact. This issue may also occur in other dental procedures besides gingival retraction, where dental paste is being applied in a region containing soft tissue that may be contacted by the dispensing end of the device. There is thus a need for an improved dispensing device for providing dental paste to a region with soft tissue.